Clematis florida Thunb.
A deciduous, or semi-evergreen, shrubby climber, growing 8 to 12 ft high, with hard, wiry stems. Leaves 3 to 5 in. long, normally composed of three divisions, which are each again divided into three leaflets. Leaflets ovate to lanceolate, 1 to 2 in. long, mostly untoothed in the cultivated forms, but often coarsely toothed in the wild; glossy dark green above, more or less hairy beneath. Flowers 21⁄2 to 3 in. across, solitary on downy stalks 3 to 4 in. long, that are furnished about the middle with a pair of stalkless, variously lobed, leaf-like bracts. Sepals from four to six, oval, pointed, fully spread, white or creamy white, with a greenish band down the back. Stamens spreading, dark (almost black) purple. Seed-vessels purplish, with silky tails. Flowers in June and July.
Native of China. It was first noticed by Thunberg in Japan, where it has long been grown in gardens; introduced in 1776. The wild ancestral form was found by Henry near Ichang in the Chinese province of Hupeh and later by Wilson in the same locality, but is probably not in cultivation. C. florida is closely allied to C. patens and the two are united by some authorities. But for garden purposes, C. patens is well distinguished in having no bracts to the flower-stalk and in the leaves consisting of three or five simple leaflets; in C. florida the leaves are doubly ternate.
cv. ‘Plena’. – Stamens transformed the same way as in ‘Sieboldii’ (see below), but white. A very old garden variety, commoner in nineteenth-century gardens than the single form, but now very rare.
cv. ‘Sieboldii’. – In this variety the flowers are ‘doubled’ through the transformation of the stamens into petal-like organs. Whilst the sepals are white, the centre of the flower is purple. A cultivated Japanese variety introduced to England from Siebold’s nursery in 1836. (var. bicolor Lindl.)
Whether C. florida is to be considered as one of the parents of the garden race of large-flowered clematises depends very much on the status of C. ‘Fortunei’. This, like ‘Sieboldii’, is a double-flowered variety of Japanese gardens, with creamy white sepals and petaloid stamens, introduced by Fortune and much used by clematis breeders in the nineteenth century. It is usually regarded as a “variety” of C. florida but is placed by Rehder under C. patens.
In gardens it is still customary to distinguish a Florida group of large-flowered clematises – all double – but in no sense, either botanical or horticultural, can these be considered as varieties of C. florida. They are hybrids of complex origin some of which may have nothing or little of C. florida in their make-up. Thus the parentage of ‘Belle of Woking’ is C. (lanuginosa × patens) × ‘Fortunei’. This clematis and others traditionally placed in the Florida group, such as ‘Duchess of Edinburgh’, require no pruning beyond the removal of the old flowering wood. This also applies to ‘Sieboldii’.